Respiration
Structure & Function
Primary Functions
1. Bringing O2 into the body
2. Get rid of CO2
3. Regulate blood pH
Structure
I. Upper respiratory tract
a. Sinuses
b. Nasal cavity
c. External nose
d. Nostril
e. Pharynx
f. Mouth
g. Tongue
h. Epiglottis
i. Glottis
j. Larynx
k. Trachea
l. Oesophagus
II. Lower respiratory tract
a. Trachea
b. Alveoli (tiny, hollow sacs of squamous epithelium; soft & spongy)
c. Rib
d. Two lobes left lung
e. Three lobes right lung
f. Bronchi
g. Bronchioli
h. Diaphragm
i. Pleural membrane + pleural cavity (filled with inner pleural fluid; hydrostatic
pressure allows for easy movement)
Gaseous Exchange
Factors affecting GE
Surface area of respiratory membrane
Thickness of respiratory membrane
Diffusion gradient between two sides
Diffusion co-efficient or gas (solubility)
Surfactant
- Alveoli contain epithelial cell that secrete a surfactant (a lipoprotein)
- Coats inside of alveoli which reduces surface tension (attraction of water molecules to each
other)
- Without it, alveoli will collapse
Structure & Function
Primary Functions
1. Bringing O2 into the body
2. Get rid of CO2
3. Regulate blood pH
Structure
I. Upper respiratory tract
a. Sinuses
b. Nasal cavity
c. External nose
d. Nostril
e. Pharynx
f. Mouth
g. Tongue
h. Epiglottis
i. Glottis
j. Larynx
k. Trachea
l. Oesophagus
II. Lower respiratory tract
a. Trachea
b. Alveoli (tiny, hollow sacs of squamous epithelium; soft & spongy)
c. Rib
d. Two lobes left lung
e. Three lobes right lung
f. Bronchi
g. Bronchioli
h. Diaphragm
i. Pleural membrane + pleural cavity (filled with inner pleural fluid; hydrostatic
pressure allows for easy movement)
Gaseous Exchange
Factors affecting GE
Surface area of respiratory membrane
Thickness of respiratory membrane
Diffusion gradient between two sides
Diffusion co-efficient or gas (solubility)
Surfactant
- Alveoli contain epithelial cell that secrete a surfactant (a lipoprotein)
- Coats inside of alveoli which reduces surface tension (attraction of water molecules to each
other)
- Without it, alveoli will collapse
